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The criteria currently used to determine the extent of novel forest decline areleaf loss andyellowing of leaves. However, these criteria have only a limited value for indicating damage of woody trees, especially the early stages. Therefore, physiological-biochemical parameters will be useful to measure the extent of forest decline. Results from several natural spruce stands indicate that in needles with early signs of damage and needles with severe damage PEPC activity is significantly higher than in needles of healthy plants. Therefore, PEPC activity can reveal beginning damage and may be used as abiochemical indicator for damage assessments of spruce. The influence of air pollutants on PEPC activity in spruce needles was measured in fumigation chambers and open-top chambers; PEPC activity was shown to be affected by long-term exposition only. 相似文献
276.
Georg E. Carlberg Elizabeth Baumann Ofstad Hilde Drangsholt Eiliv Steinnes 《Chemosphere》1983,12(3):341-356
Moss and lichen samples from eleven remote sites from all parts of Norway were analysed for persistent chlorinated hydrocarbons. The highest and lowest concentration levels were found in the most southwesterly and northerly locations, respectively. Moss and lichen samples from one site were also analysed for other organic micropollutants. They were found to contain alkanes, mostly of biogenic origin, PAH and phthalates. 相似文献
277.
Klaus Schneider Jan Oltmanns Thomas Radenberg Thomas Schneider Dagmar Pauly-Mundegar 《Environmental science and pollution research international》1996,3(3):135-138
The uptake of nitroaromatic compounds by plants from the soil was studied at an ammunition site. After the development of analytical methods for 2,4,6-trinitrotoluene, aminodinitrotoluenes and dinitrotoluenes in plant material, we could show that these substances accumulated in the roots of plants and are found to a lesser extent inleaves and stems. We observed only moderate differences between various plant species. It is likely that a metabolic transformation in plants leads to the formation of dinitrotoluenes which are considered to be potent carcinogens. Results from soils with a wide range of explosive concentrations show a good correlation between the plant and soil concentrations. The relative accumulation in plant material is higher at lower soil concentrations. At low soil concentrations of about 1 mg trinitrotoluene/kg soil, an accumulation factor of about 0.5 can be derived. These data are an important input for the risk assessment of ammunition sites. 相似文献
278.
Kang D Eder BK Stein AF Grell GA Peckham SE McHenry J 《Journal of the Air & Waste Management Association (1995)》2005,55(12):1782-1796
The National Oceanic and Atmospheric Administration recently sponsored the New England Forecasting Pilot Program to serve as a "test bed" for chemical forecasting by providing all of the elements of a National Air Quality Forecasting System, including the development and implementation of an evaluation protocol. This Pilot Program enlisted three regional-scale air quality models, serving as prototypes, to forecast ozone (O3) concentrations across the northeastern United States during the summer of 2002. A suite of statistical metrics was identified as part of the protocol that facilitated evaluation of both discrete forecasts (observed versus modeled concentrations) and categorical forecasts (observed versus modeled exceedances/nonexceedances) for both the maximum 1-hr (125 ppb) and 8-hr (85 ppb) forecasts produced by each of the models. Implementation of the evaluation protocol took place during a 25-day period (August 5-29), utilizing hourly O3 concentration data obtained from over 450 monitors from the U.S. Environment Protection Agency's Air Quality System network. 相似文献
279.
Saulo R. Freitas Karla M. Longo Maria A. F. Silva Dias Pedro L. Silva Dias Robert Chatfield Elaine Prins Paulo Artaxo Georg A. Grell Fernando S. Recuero 《Environmental Fluid Mechanics》2005,5(1-2):135-167
The atmospheric transport of biomass burning emissions in the South American and African continents is being monitored annually using a numerical simulation of air mass motions; we use a tracer transport capability developed within RAMS (Regional Atmospheric Modeling System) coupled to an emission model. Mass conservation equations are solved for carbon monoxide (CO) and particulate material (PM2.5). Source emissions of trace gases and particles associated with biomass burning activities in tropical forest, savanna and pasture have been parameterized and introduced into the model. The sources are distributed spatially and temporally and assimilated daily using the biomass burning locations detected by remote sensing. Advection effects (at grid scale) and turbulent transport (at sub-grid scale) are provided by the RAMS parameterizations. A sub-grid transport parameterization associated with moist deep and shallow convection, not explicitly resolved by the model due to its low spatial resolution, has also been introduced. Sinks associated with the process of wet and dry removal of aerosol particles and chemical transformation of gases are parameterized and introduced in the mass conservation equation. An operational system has been implemented which produces daily 48-h numerical simulations (including 24-h forecasts) of CO and PM2.5, in addition to traditional meteorological fields. The good prediction skills of the model are demonstrated by comparisons with time series of PM2.5 measured at the surface. 相似文献
280.
Georg Wanior Rainer Stempel Thomas Rosenberger Dieter Baumgarten Thomas Schmid Walter Hempe 《Environmental Sciences Europe》1996,8(6):335-341
Various analyses and evaluative procedures are used to provide evidence of success using remediation procedures. Because of the lack of standardized procedures for soil assessment, general practice has unfortunately propagated the use of DIN standards for determining the level of similar parameters in water as well as for other heterogeneous matrices (e.g. in soil). A precise auditing of quality, however, has not been possible with this method, this procedure has even put the success of such a remediation into question. This article describes the problems of determining mineral hydrocarbon concentrations on soil as well as portraying the remediation of oil damages which has occurred on a site of a former waste oil redestillation facility [1, 2]. This procedure has been proved in practice and serves as a model because an adequately defined, standardized method (DIN standard) is lacking. 相似文献